1. Field of the Invention
The present invention relates to a broadband coupling filter, and more particularly, to a broadband coupling filter capable of generating a notch filtering effect.
2. Description of the Prior Art
A filter is an electronic element widely used for allowing signals within a specific frequency band, while attenuating or rejecting signals outside the frequency band. In general, a filter is composed of passive elements, such as resistors, capacitors and inductors, and thus an operating frequency band of a filter is unlikely to be extended, which causes disadvantages in broadband applications.